Various types of showerhead cleaning apparatuses are known in the prior art. However, what is needed is a showerhead cleaning adapter that includes a pipe member having a male end and a female end disposed for positioning between an extant showerhead and an extant manifold, said pipe member including a flow controlling side inlet pipe valve disposed to releasably interconnect a cartridge therein, said cartridge discharging cleaning solution into said showerhead when attached to, and depressed within, an interconnect portion of the side inlet pipe valve, wherein cleaning solution is selectively releasable to clean and disinfect an extant showerhead interior.